1. Field of the Invention
The present invention relates generally to a toner cartridge and a mechanism of installing and removing the same for use in an image forming apparatus, such as a copying machine. More specifically, the present invention relates to a toner cartridge and a mechanism of installing and removing the same suitable for replacement of the toner cartridge.
2. Description of the Related Art
In a typical image forming apparatus such as a copying machine, printed information is generated on paper from image information as given to be copied by electrifying the surface of a photoreceptor drum, exposing the electrified surface of the photoreceptor drum to the image information to form a latent image, attracting toner to the photoreceptor drum to form a visible image, transferring the visible image of the toner to a sheet of paper, applying heat and pressure to the sheet of paper to fix the image information onto the sheet of paper, and cleaning and neutralizing the sheet of paper. In the developing process of forming the visible image, the toner is used as developer as well as a carrier made of a magnetic material.
The carrier which is a main component of the developer is used to provide electricity by frictional electrification and transport the toner. This carrier is used to electrify the photoreceptor drum for the purpose of attracting the toner onto the photoreceptor drum and then transferring it to paper, and therefore the carrier shall not be consumed and decreased by its attachment to paper. In contrast to this, while printed material is produced by transferring, fixation, cleaning and the like steps, the toner is consumed after each use and becomes gradually less. Accordingly, after the use of the image forming apparatus for a certain period of time, the toner must be supplied.
In order to appropriate supplying toner from a toner cartridge while preventing toner leakage during a replacement operation, it is proposed that a cap is attached to the toner container of a toner cartridge, and fitted into a cylindrical cover which is displaced in use to open a discharge port of the cap through which toner can be discharged by rotating in this state the toner container and moving forward the toner, while the cover serves to close the discharge port for example when this toner cartridge is removed in order to prevent leakage of toner (for example, as described in Japanese Patent Published Application No. 2001-235935).
However, in the case of replacement of such a conventional toner cartridge, the toner cartridge is pulled out from the main unit by putting hand on a suitable location of the toner cartridge so that the toner cartridge may be loose and sometimes broken.